Bad or worn out Redhead steering box?
 

My brothers 92 W250 has redhead power steering box installed but steering is really loose and has shimmy going down the road. We've tried adjusting it but it would tighten up to point where steering wheel would be hard to turn but there's still slop in steering. Ive taken video of me twisting steering shaft and there's nothing happening at the other end of steering gear. Is this bad box that needs to be rebuilt?
https://www.youtube.com/watch?v=bokq...ature=youtu.be

I believe that adjusting the box is a mistake. There is a procedure to set up the box and it is really not a field adjustment. There are a few things that can cause these symptoms, tie rod ends, king pins, king pin bushings, springs and some that I can't remember right now. The redhead could be bad, but it certainly needs to be adjusted again...Mark

Looks like the box has developed a bit of a dead spot in the middle. My recently installed 'good used' box is about the same.

Most likely need to increase your caster angle to get rid of the shimmy and prolong box life.

I have never seen good things come from adjusting a box like that on a truck.

So you're saying box is worn out and needs replaced?

It needs to be at least checked, but probably yes. I would check all of the other steering components at the time, including the king pins, because the wobble could be unrelated to the play in the steering. How many miles on the truck?..Mark

Take a video with the truck running and do that by hand. If you move it... it should send power to the output and that will give you a rough idea if it's worn. If you adjusted it, though, you will mess up the turns on the steering wheel and you will not get sensitivity because from redhead they're at top center.

The steering shaft play is pretty normal, I bet the steering wheel is moving as well :P I can't remember the ratio on those gearboxes, 18:1 seems right but I don't remember.

I'm forever amazed that folks don't do their homework, and just start tightening things that are only supposed to be done on a bench by a seasoned pro who knows what they're doing.

Call redhead and tell them whats happening. Pretty sure they have a lifetime guarantee on their box rebuilds.... At least until someone messes with the preload adjustment